http://dspace.nbuv.gov.ua:80/handle/123456789/150379 Sat, 18 Apr 2026 21:24:19 GMT 2026-04-18T21:24:19Z http://dspace.nbuv.gov.ua:80/bitstream/id/472566/ http://dspace.nbuv.gov.ua:80/handle/123456789/150379 http://dspace.nbuv.gov.ua:80/handle/123456789/158466 Joseph Solomonovich Ponizovskii (1928 – 2012) Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/158466 2013-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/152316 The monoid of endomorphisms of disconnected hypergraphs Zhuchok, Yu.V. We prove that the monoid of endomorphisms of an arbitrary disconnected hypergraph is isomorphic to a wreath product of a transformation semigroup with a certain small category. For disconnected hypergraphs we also study the structure of the monoid of strong endomorphisms and the group of automorphisms. Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/152316 2013-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/152315 On one class of partition polynomials Zatorsky, R.; Stefluk, S. We consider relations between one class of partition polynomials, parafunctions of triangular matrices (tables), and linear recurrence relations. Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/152315 2013-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/152314 Inverse semigroups generated by group congruences. The Möbius functions Schwab, E.D. The computation of the Möbius function of a Möbius category that arises from a combinatorial inverse semigroup has a distinctive feature. This computation is done on the field of finite posets. In the case of two combinatorial inverse semigroups, order isomorphisms between corresponding finite posets reduce the computation to one of the semigroups. Starting with a combinatorial inverse monoid and using a group congruence we construct a combinatorial inverse semigroup such that the Möbius function becomes an invariant to this construction. For illustration, we consider the multiplicative analogue of the bicyclic semigroup and the free monogenic inverse monoid. Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/152314 2013-01-01T00:00:00Z